import type { IAction, IActorArgs, IActorOutput, IActorTest, Mediate } from '@comunica/core';
import { Actor } from '@comunica/core';
import type { IActionContext } from '@comunica/types';
/**
 * A comunica actor for context-preprocess events.
 *
 * Actor types:
 * * Input:  IAction:      A context that will be processed.
 * * Test:   <none>
 * * Output: IActorContextPreprocessOutput: The resulting context.
 *
 * @see IActionContextPreprocess
 * @see IActorContextPreprocessOutput
 */
export declare abstract class ActorContextPreprocess<TS = undefined> extends Actor<IActionContextPreprocess, IActorTest, IActorContextPreprocessOutput, TS> {
    /**
     * @param args -
     *   \ @defaultNested {<default_bus> a <cc:components/Bus.jsonld#Bus>} bus
     *   \ @defaultNested {Context preprocessing failed} busFailMessage
     */
    constructor(args: IActorContextPreprocessArgs<TS>);
}
export interface IActionContextPreprocess extends IAction {
    /**
     * If the query processing is being initialized.
     * This is typically used for setting query-wide defaults.
     * This will be false for initializing source-specific contexts.
     */
    initialize?: boolean;
}
export interface IActorContextPreprocessOutput extends IActorOutput {
    /**
     * A context object.
     * Can be null.
     */
    context: IActionContext;
}
export type IActorContextPreprocessArgs<TS = undefined> = IActorArgs<IActionContextPreprocess, IActorTest, IActorContextPreprocessOutput, TS>;
export type MediatorContextPreprocess = Mediate<IActionContextPreprocess, IActorContextPreprocessOutput>;